Ultimate load-carrying behavior of butt joints of marine CFRP stiffened plates

Objectives To investigate the ultimate bearing characteristics of butt-jointed carbon fiber reinforced stiffened plates applied in ship superstructures, bending tests and numerical simulations were conducted on such structures under bending loads. Methods Firstly, three-point bending tests were carried out on the butt-jointed carbon fiber reinforced stiffened plates considering the out-of-plane loads borne by ships during navigation. Secondly, a finite element model was established to perform simulation analysis of the stiffened plate butt structure under bending loads. Combined with the Hashin failure criterion and Tserpes stiffness degradation model, a user-defined material subroutine (VUSDFLD) was compiled and implemented in ABAQUS/Explicit. Finally, the experimental and numerical simulation results were compared in terms of ultimate bearing capacity and failure modes to verify the validity of the established numerical simulation model. Results The results indicate that under bending loads, the damage of the butt-jointed carbon fiber reinforced stiffened plates initiates from the core material of hat-shaped stiffeners and gradually propagates to the face plates until final structural failure occurs. Conclusions This research provides an engineering reference for the study on damage behaviors of adhesively-bolted hybrid connected butt-jointed carbon fiber reinforced stiffened plates and the strength analysis of ship superstructures.